Electronic weighing systems are generally known and include a weighing platform or container adapted to support a mass the weight of which is to be measured, and one or more load cells coupled to the weighing platform and operative to provide an analog signal representative of sensed weight. The analog output signal is converted to digital form by an analog-to-digital converter and the digital signal subsequently processed to provide an output indication of weight which may be employed for purposes of display, automatic control or the like. Weight is determined by measuring the force exerted upon the weighing platform by the mass being measured, and if a measurement is taken before the platform has settled, an inaccurate weight measurement can result.
Various techniques have been proposed to detect weighing platform motion in order to inhibit erroneous output data. In a typical motion sensing circuit of the prior art, digital representations of weight at successive time intervals are stored in data registers and the stored digital data compared to ascertain the magnitude difference therebetween. Other techniques proposed are based on an analog rate measurement achieved by differentiation of the analog weight signal.